This is too cool for words, but I'll try anyway. In his book, Dan talked a lot about how he'd get complaints about tone and such and the first thing he said was, "Change the strings!." So your 6120 needed a fret job, set-up and Dan signed off on it. Did you just find this? You should make a pic of your old 6120 and keep it with this for posterity.

Oh, and it's really nice to see something new here, as much as I like re-reading DCBirdMan's Matt Umanov interview.